The present invention relates to a novel color-developing agent, a silver halide photographic light-sensitive material and image-forming method using the color-developing agent. Particularly, the present invention relates to a silver halide photographic light-sensitive material which is excellent in color-forming property in the developing stage and in storability of an image, and to an image-forming method utilizing the light-sensitive material.
Further, the present invention relates to a color diffusion transfer type silver halide photographic light-sensitive material comprising a novel diffusible dye-forming color-developing agent and a coupler, and to an image-forming method using the light-sensitive material. Particularly, the present invention relates to a color diffusion transfer type silver halide photographic light-sensitive material excellent in storability and sharpness of an image, and to an image-forming method using the light-sensitive material.
In a color photographic light-sensitive material, when it is exposed and thereafter color-developed, the oxidized color-developing agent is reacted with a coupler to form an image.
The color-developing is attained, for instance, by dipping an exposed light-sensitive material in an aqueous alkali solution (a developing solution) in which a color-developing agent is dissolved. This technique have many problems, for example, a problem that the developing solution tends to be deteriorated with the lapse of time and problems concerning treatments of developing solution wastes.
As one effective measure to solve above problems, a method wherein an aromatic primary amine developing agent or its precursor is built in the hydrophilic colloid layer of a light-sensitive material is proposed. Further, a method wherein a sulfonylhydrazine-type developing agent is built in the hydrophilic colloid layer of a light-sensitive material is proposed. Examples of these include methods described, for example, in U.S. Pat. No. 803 783, JP-B-58-14671 (xe2x80x9cJP-Bxe2x80x9d means examined Japanese patent publication), European Patent Nos. 545 491(A1) and 565 165(A1).
However, even these methods cannot attain satisfactory color formation when color-developed; and there is the problem of storage stability.
In the fields of silver halide photographic light-sensitive materials, a so-called color diffusion transfer method in which a diffusible dye is formed imagewise on a light-sensitive material and the image is transferred and fixed to an image-receiving material, to form a color image, is known technique, and many proposals concerned this have been made. Adopted in these methods is a method in which a diffusible dye is generally formed, as a function of developing of silver halide, from a compound (hereinafter called a colorant) produced by modifying a pre-colored image-forming dye (pre-formed dye) to one which is resistant to diffusion. In the method like this, when the colorant is added to the same layer as a silver halide emulsion, an unacceptable reduction in sensitivity to exposure is caused by a filter effect of a dye portion. Hence, generally, in order not to face the problem, a method is adopted in which an image-forming colorant is added to a layer more apart from the exposed surface with respect to the silver halide emulsion layer. In this method, although the above reduction in sensitivity which is caused by the filter effect is avoided, there is an inherent drawback that developing information is transferred from the silver halide emulsion to the colorant inefficiently because the physical distance between the silver halide emulsion and the colorant is large.
In order to improve these drawbacks, a so-called coupling system is proposed in U.S. Pat. No. 4469773 and JP-B-63-36487 in which system a dye is formed by a coupling reaction between an oxidized product of a developing agent, which is produced as a function of the developing of silver halide, and a coupler. However, the color-developing agent described therein has a difficulty in the compatibility of the storage stability and the activity of the coupling reaction and a difficulty in modifying both the color-developing agent and the coupler to those having resistance to diffusion.
Novel color-developing agents are proposed in JP-A-09-152702 (xe2x80x9cJP-Axe2x80x9d means unexamined published Japanese patent application) and JP-A-09-152705. In these methods, however, sufficient color-forming property is not obtained yet. Also, whether or not there are problems concerning the hue and color image stability of a dye to be formed, or the color image stability of a dye to be formed is not mentioned in those publications at all.
Particularly, the compounds described in the said JP-A-9-152705 have the drawbacks that sharpness of a magenta dye to be formed is insufficient and the storage stability of a color image is also insufficient.
In JP-A-9-152702, there is a proposal concerning a heterocyclic hydrazine developing agent having two or more nitrogen atoms. However, in this publication, there is no specific description concerning diffusion transfer type silver halide photographic light-sensitive materials and there is also nothing referring to specific properties (e.g., hue and stability) of a dye to be formed.
It is an object of the present invention to provide a novel color-developing agent. It is another object of the present invention to provide a silver halide photographic light-sensitive material which gives sufficient color formation by development and forms an image excellent in image quality and image storability, by using the color-developing agent. Still another object of the present invention is to provide an image-forming method using the light-sensitive material.
Further another object of the present invention is to provide a method for forming a diffusible magenta dye from a colorless color-developing agent and a colorless coupler, in which the magenta dye to. be formed in this method is excellent in sharpness and storage stability. Still another object of the present invention is to provide a color diffusion transfer type silver halide photographic light-sensitive material which makes it possible to obtain sufficient color formation upon development and to form a color transfer image of excellent image quality. Another object of the present invention is to provide an image-forming method using the light-sensitive material.
Other and further objects, features, and advantages of the invention will appear more fully from the following description.
The present inventors found that the above objects of the present invention can be attained by the following means.
(1) A color-developing agent represented by the following formula.(1): 
wherein X represents a substituent that has, as a substituent on the substituent, at least one substituent represented by xe2x80x94COOH, xe2x80x94NHSO2R, xe2x80x94SO2NHR, xe2x80x94SO2NHCOR, xe2x80x94CONHSO2R, xe2x80x94OH or xe2x80x94SH, in which R represents an alkyl group, an aryl group or an aromatic heterocyclic group, each of which may be substituted, and Z represents a carbamoyl group, an acyl group, an alkoxycarbonyl group or an aryloxycarbonyl group.
(2) The color-developing agent according to the above (1), wherein Z in the formula (1) is a carbamoyl group, which is a carbamoyl group having one or more hydrogen atoms bonded.on the nitrogen atom of the carbamoyl group.
(3) A silver halide photographic light-sensitive material containing at least one color-developing agent represented by formula (1) stated in the above (1), in at least one hydrophilic colloid layer provided on a support.
(4) An image forming method, comprising subjecting the silver halide photographic light-sensitive material according to the above (3), to imagewise exposure, and subjecting the resultant light-sensitive material to development.
(5) The image forming method as stated in the above (4), wherein the development step comprises subjecting the silver halide photographic light-sensitive material to heat development.
(6) The image forming method as stated in the above (4), wherein the development step comprises subjecting the silver halide photographic light-sensitive material to development, in the presence of an alkali generated from a metal salt which is sparingly soluble in water and a complexing agent of the metal salt.
(7) The image forming method as stated in the above (4), wherein the development step comprises subjecting the color diffusion transfer type silver halide photographic light-sensitive material to development with an alkali processing solution.
(8) A color-developing agent represented by the following formula (2): 
wherein X1 represents a halogen atom, an alkylthio group, an alkylsulfinyl group, an alkylsulfonyl group, an arylthio group, an arylsulfinyl group, an arylsulfonyl group or a sulfamoyl group, provided that a further substituent which can be substituted on X1 excludes a hydroxy group, a carboxyl group, a mercapto group, an aminosulfonyl group, a carbonylaminosulfonyl group, a sulfonylamino group and a sulfonylaminocarbonyl group, Z1 represents a carbamoyl group, an acyl group, an alkoxycarbonyl group or an aryloxycarbonyl group.
(9) The color-developing agent according to the above (8), wherein Z1 in the formula (2) is a carbamoyl group, which is a carbamoyl group having one or more hydrogen atoms bonded on the nitrogen atom of the carbamoyl group.
(10) A silver halide photographic light-sensitive material containing at least one color-developing agent represented by formula (2) stated in the above-(8), in at least one hydrophilic colloid layer provided on a support.
(11) An image forming method, comprising subjecting the silver halide photographic light-sensitive material according to the above (10), to imagewise exposure, and subjecting the resultant light-sensitive material to development.
(12) The image forming method as stated in the above (11), wherein the development step comprises subjecting the silver halide photographic light-sensitive material to heat development.
(13) The image forming method as stated in the above (11), wherein the development step comprises subjecting the silver halide photographic light-sensitive material to development, in the presence of an alkali generated from a metal salt which is sparingly soluble in water and a complexing agent of the metal salt.
(14) The image forming method as stated in the above (11), wherein the development step comprises subjecting the color diffusion transfer type silver halide photographic light-sensitive material to development with an alkali processing solution.
(15) A color diffusion transfer type silver halide photographic light-sensitive material comprising at least one color-developing agent represented by the following formula (3) and at least one coupler represented by the following formula (4), in at least one hydrophilic colloid layer provided on a support: 
wherein X2 represents an alkyl group or an aryl group, and Z2 represents a carbamoyl group, an acyl group, an alkoxycarbonyl group or an aryloxycarbonyl group: 
wherein R1 represents a substituent, m is an integer from 0 to 4, in which when m is 2 or more, R1s may be the same or different and may form a five- to seven-membered ring between them, Y1 represents an aryl group, an unsaturated heterocyclic group, an acyl group, an alkoxycarbonyl group, an aryloxycarbonyl group, a carbamoyl group or a sulfonyl group, in which the groups each have an alkyl group and the sum of carbon atoms thereof are 6 or more in total.
(16) The color diffusion transfer type silver halide photographic light-sensitive material according to the above (15), wherein Z2 in the formula (3) is a carbamoyl group, which is a carbamoyl group having one or more hydrogen atoms bonded on the nitrogen atom of the carbamoyl group.
(17) The color diffusion transfer type silver halide photographic light-sensitive material according to the above (15), wherein Y1 in the formula (4) is an alkoxycarbonyl group or a carbamoyl group, in which the groups each have an alkyl group and the sum of carbon atoms thereof are 6 or more in total.
(18) An image forming method, comprising subjecting the color diffusion transfer type silver halide photographic light-sensitive material according to the above (15), (16) or (17), to imagewise exposure, and subjecting the resultant light-sensitive material to development.
(19) The image forming method as stated in the above (18), wherein the development step comprises subjecting the color diffusion transfer type silver halide photographic light-sensitive material to heat development.
(20) The image forming method as stated in the above (18), wherein the development step comprises subjecting the color diffusion transfer type silver halide photographic light-sensitive material to development, in the presence of an alkali generated from a metal salt which is sparingly soluble in water and a complexing agent of the metal salt.
(21) The image forming method as stated in the above (18), wherein the development step comprises subjecting the color diffusion transfer type silver halide photographic light-sensitive material to development with an alkali processing solution.
Herein, the color-developing agents as stated in the above (1) and (2), the silver halide photographic light-sensitive material as stated in the above (3), and the image-forming methods as stated in the above (4) to (7) are referred to as the first embodiment of the present invention.
Further, the color-developing agents as stated in the above (8) and (9), the silver halide photographic light-sensitive material as stated in the above (10), and the image-forming methods as stated in the above (11) to (14) are referred to as the second embodiment of the present invention.
In addition, the color diffusion transfer type silver halide photographic-light-sensitive materials as stated in the above (15) to (17), and the image-forming methods as stated in the above (18) to (21) are referred to as the third embodiment of the present invention.
In the-following description, the present invention means to include all of the above first, second, and third embodiments, unless otherwise specified.
Herein, in the present specification and claims, a group on a compound includes both a group having a substituent thereon and a group having no substituent (i.e. an unsubstituted group), unless otherwise specified.
The compound represented by the formula (1), which is used in the first embodiment of the present invention will be explained in detail below.
Examples of the substituent represented by X in the formula (1) include an alkyl group (e.g., a methyl group, ethyl group and benzyl group), an aryl group (e.g., a phenyl group, naphthyl group and m-nitrophenyl group), an alkylthio group (e.g., a methylthio group, ethylthio group and benzylthio group), an alkylsulfinyl group (e.g., a methanesulfinyl group and ethanesulfinyl group), an alkylsulfonyl group (e.g., a methanesulfonyl group, ethanesulfonyl group and benzylsulfonyl group), an arylthio group (e.g., a phenylthio group, naphthylthio group and 4-methoxyphenylthio group), an arylsulfinyl group (e.g., benzenesulfinyl group and naphthalenesulfinyl group), an arylsulfonyl group (e.g., benzenesulfonyl groups, p-toluenesulfonyl group and p-methanesulfonylbenzenesulfonyl group) and a sulfamoyl group (e.g., an N-butylsulfamoyl group and N,N-diethylsulfamoyl group). Preferably each of these groups has 1 to 50 carbon atoms and more preferably 1 to 20 carbon atoms. Further these groups respectively have at least one substituent represented by xe2x80x94COOH, xe2x80x94NHSO2R, xe2x80x94SO2NHR, xe2x80x94SO2NHCOR, xe2x80x94CONHSO2R, xe2x80x94OH or xe2x80x94SH, in which R represents an alkyl group, an aryl group or an aromatic heterocyclic group.
Among these groups, the substituent represented by X is preferably an alkyl group, aryl group, alkylthio group, alkylsulfonyl group, arylthio group or arylsulfonyl group.
The substituent that X has is preferably xe2x80x94NHSO2R, xe2x80x94SO2NHR, xe2x80x94SO2NHCOR, xe2x80x94CONHSO2R or xe2x80x94OH, and more preferably xe2x80x94NHSO2R or xe2x80x94SO2NHR, in which R represents an alkyl group (e.g., a methyl group, ethyl group or benzyl group), an aryl group (e.g., a phenyl group, naphthyl group or m-nitrophenyl group) or an aromatic heterocyclic group (e.g., a 2-pyridyl group, 4-pyridyl group or 2-furyl group), and preferably an alkyl group or aryl group.
Z represents a carbamoyl group, acyl group, alkoxycarbonyl group or aryloxycarbonyl group. Among these groups, a carbamoyl group is preferable and a carbamoyl group having one or two hydrogen atom(s), and more preferably one hydrogen atom bonded on the nitrogen atom is particularly preferable.
As the carbamoyl group, those having 1-50 carbon atoms are preferable and those having 8-40 carbon atoms are more preferable. Specific examples of the carbamoyl group include a hexadecylcarbamoyl group, octadecylcarbamoyl group, 3-(2,4-di-tert-pentylphenoxy)propylcarbamoyl group, 4-dodecyloxyphenylcarbamoyl group, 2-chloro-5-dodecyloxycarbonylphenylcarbamoyl group and naphthylcarbamoyl group.
The aforementioned groups each may further have a substituent, and examples of the further substituent include a cyano group, a carboxyl group, a sulfo group, a hydroxy group, a nitro group, a mercapto group, a halogen atom (a fluorine atom, chlorine atom, bromine atom and iodine atom), an alkyl group (an alkyl group which has generally 30 or less carbon atoms and preferably 8 or less carbon atoms and may be substituted, for example, a methyl group, trifluoromethyl group, benzyl group, dimethylaminomethyl group, ethoxycarbonylmethyl group, acetylaminomethyl group, ethyl group, carboxyethyl group, allyl group, n-propyl group, iso-propyl group, n-butyl group, t-butyl group, t-pentyl group, cyclopentyl group, n-hexyl group, t-hexyl group, cyclohexyl group, t-octyl group, n-decyl group, n-undecyl.group and n-dodecyl group), an aryl group (an aryl group which has generally 30 or less carbon atoms and preferably 10 or less carbon atoms and may be substituted, for example, a phenyl group, naphthyl group, 3-hydroxyphenyl group, 3-chlorophenyl group, 4-acetylaminophenyl group, 2-methanesulfonylphenyl group, 4-methoxy phenyl group, 4-methanesulfonylphenyl group and 2,4-dimethylphenyl group), a heterocyclic group (a heterocyclic group which has generally 30 or less carbon atoms and preferably 10 or less carbon atoms and may be substituted, for example, a 1-imidazolyl group, 2-furyl group, 2-pyridyl group, 3-pyridyl group, 3,5-dicyano-2-pyridyl group, 5-tetrazolyl group, 5-phenyl-1-tetrazolyl group, 2-benzthiazolyl group, 2-benzimidazolyl group, 2-benzoxazolyl group, 2-oxazoline-2-yl group and morpholino group), an acyl group (an acyl group which has generally 20 or less carbon atoms and preferably 8 or less carbon atoms and may be substituted, for example, an acetyl group, propionyl group, butyroyl group, iso-butyroyl group, 2,2-dimethylpropionyl group, benzoyl group, 3,4-dichlorobenzoyl group, 3-acetylamino-4-methoxybenzoyl group and 4-methylbenzoyl gtoup), a sulfonyl group (a sulfonyl group which has generally 20 or less carbon atoms and preferably 8 or less carbon atoms and may be substituted, for example, a methanesulfonyl group, ethanesulfonyl group, chloromethanesulfonyl group, propanesulfonyl group, butanesulfonyl group, n-octanesulfonyl group, n-dodecanesulfonyl group, benzenesulfonyl group and 4-methylphenylsulfonyl group), an alkoxy group (an alkoxy group which has generally 20 or less carbon atoms and preferably 8 or less carbon atoms and may be substituted, for example, a methoxy group, ethoxy group, n-propyloxy group, iso-propyloxy group and cyclohexylmethoxy group), an aryloxy group or heteroaryloxy group (an aryloxy group or heteroaryloxy group which has generally 20 or less carbon atoms and preferably 10 or less carbon atoms and may be substituted, for example, a phenoxy group, naphthyloxy group, 4-acetylaminophenoxy group, pyrimidine-2-yloxy group and 2-pyridyloxy group), a silyloxy group (a silyloxy group which has generally 10 or less carbon atoms and preferably 8 or less carbon atoms and may be substituted, for example, a trimethylsilyloxy group and tert-butyldimethylsilyloxy group), an alkylthio group (an alkylthio group which has generally 20 or less carbon atoms and preferably 8 or less carbon atoms and may be substituted, for example, a methylthio group, ethylthio group, n-butylthio group, n-octylthio group, t-octylthio group, ethoxycarbonylmethylthio group, benzylthio group and 2-hydroxyethylthio group), an arylthio group or heteroarylthio group (an arylthio or heteroarylthio group which has generally 20 or less carbon atoms and preferably 10 or less carbon atoms and may be substituted, for example, a phenylthio group, 4-chlorophenylthio group, 2-n-butoxy-5-t-octylphenylthio group, 4-nitrophenylthio group, 2-nitrophenylthio group, 4-acetylaminophenylthio group, 1-phenyl-5-tetrazolylthio group, 5-methanesulfonylbenzothiazole-2-yl group), a carbamoyl group (a carbamoyl group which has generally 20 or less carbon atoms and preferably 8 or less carbon atoms and may be substituted, for example, a carbamoyl group, methylcarbamoyl group, dimethylcarbamoyl group, bis-(2-methoxyethyl)carbamoyl group, diethylcarbamoyl group, cyclohexylcarbamoyl group and di-n-octylcarbamoyl group), a sulfamoyl group (a sulfamoyl group which has generally 20 or less carbon atoms and preferably 8 or less carbon atoms and may be substituted, for example, a sulfamoyl group, methylsulfamoyl group, dimethylsulfamoyl group, bis-(2-methoxyethyl)sulfamoyl group, diethylsulfamoyl group, di-n-butylsulfamoyl group, methyl-n-octylsulfamoyl group, 3-ethoxypropylmethylsulfamoyl group and N-phenyl-N-methylsulfamoyl group), an acylamino group (an acylamino group which has generally 20 or less carbon atoms and preferably 8 or less carbon atoms and may be substituted, for example, an acetylamino group, 2-carboxybenzoylamino group, 3-nitrobenzoylamino group, 3-diethylaminopropanoylamino group and acryloylamino group), a sulfonylamino group (a sulfonylamino group which has generally 20 or less carbon atoms and preferably 8 or less carbon atoms and may be substituted, for example, a methanesulfonylamino group, benzenesulfonylamino group and 2-methoxy-5-n-methylbenzenesulfonylamino group), an alkoxycarbonylamino group (an alkoxycarbonylamino group which has generally 20 or less carbon atoms and preferably 8 or less carbon atoms and may be substituted, for example, a methoxycarbonylamino group, ethoxycarbonylamino group, 2-methoxyethoxycarbonylamino group, iso-butoxycarbonylamino group, benzyloxycarbonylamino group, t-butoxycarbonylamino group and 2-cyanoethoxycarbonylamino group), an alkoxycarbonyloxy group (an alkoxycarbonyloxy group which has generally 20 or less carbon atoms and preferably 8 or less carbon atoms and may be substituted, for example, a methoxycarbonyloxy group, ethoxycarbonyloxy group and methoxyethoxycarbonyloxy group), an aryloxycarbonylamino group (an aryloxycarbonylamino group which has generally 20 or less carbon atoms and preferably 8 or less carbon atoms and may be substituted, for example, a phenoxycarbonylamino group, 2,4-nitrophenoxycarbonylamino-group and 4-t-butoxyphenoxycarbonylamino group), an aminocarbonylamino group (an aminocarbonylamino group which has generally 20 or less carbon atoms and preferably 8 or less carbon atoms and may be substituted, for example, a methylaminocarbonylamino group, morpholinocarbonylamino group, diethylaminocarbonylamino group, N-ethyl-N-phenylaminocarbonylamino group, 4-cyanophenylaminocarbonylamino group and 4-methanesulfonylaminocarbonylamino group), an aminocarbonyloxy group (an aminocarbonyloxy group which has generally 20 or less carbon atoms and preferably 8 or less carbon atoms and may be substituted, for example, a dimethylaminocarbonyloxy group and pyrrolidinocarbonyloxy group),an aminosulfonylamino group (an aminosulfonylamino group which has generally 20 or less carbon atoms and preferably 8 or less carbon atoms and may be substituted, for example, a diethylaminosulfonylamino group, di-n-butylaminosulfonylamino group and phenylaminosulfonylamino group), an amino group (an amino group which has generally 30 or less carbon atoms and preferably 8 or less carbon atoms and may be substituted, for example, an amino group, methylamino group, dimethylamino group, ethylamino group, ethyl-3-carboxypropylamino group, ethyl-2-sulfoethylamino group, phenylamino group, methylphenylamino group and methyloctylamino group), an alkoxycarbonyl group (an alkoxycarbonyl group which has generally 20 or less carbon atoms and preferably 6 or less carbon atoms and may be substituted, for example, a methoxycarbonyl group, ethoxycarbonyl group and methoxyethoxycarbonyl group), an aryloxycarbonyl group (an aryloxycarbonyl group which has generally 20 or less carbon atoms and preferably 10 or less carbon atoms and may be substituted, for example, a phenoxycarbonyl group and p-methoxyphenoxycarbonyl group), an acyloxy group (an acyloxy group which has generally 20 or less carbon atoms and preferably 8 or less carbon atoms and may be substituted, for example, an acetoxy group, benzoyloxy group, 2-butenoyloxy group and 2-methylpropanoyloxy group), an aryloxycarbonyloxy group (an aryloxycarbonyloxy group which has generally 20 or less carbon atoms and preferably 8 or less carbon atoms and may be substituted, for example, a phenoxycarbonyloxy group, 3-cyanophenoxycarbonyloxy group, 4-acetoxyphenoxycarbonyloxy group and 4-t-butoxycarbonylaminophenoxycarbonyloxy group), and a sulfonyloxy group (a sulfonyloxy group which has generally 20 or less carbon atoms and preferably 8 or less carbon atoms and may be substituted, for example, a phenylsulfonyloxy group, methanesulfonyloxy group, chloromethanesulfonyloxy group, 4-chlorophenylsulfonyloxy group and dodecylsulfonyloxy group).
Next, examples of the color-developing agent represented by the formula (1) will be explained. However, the scope of the present invention is not limited to these exemplified examples. 
Next, the compound represented by the formula (2), which is used in the second embodiment of the present invention will be explained in detail.
X1 in the formula (2) represents a halogen atom (e.g., a chlorine atom and bromine atom), an alkylthio group (e.g., a methylthio group, ethylthio group and cyanomethylthio group) which may have a substituent, an alkylsulfinyl group (e.g., a methanesulfinyl group and ethanesulfinyl group) which may have a substituent, an alkylsulfonyl group (e.g., a methanesulfonyl group, ethanesulfonyl group and benzylsulfonyl group) which may have a substituent, an arylthio group (e.g., a phenylthio group, naphthylthio group and 4-methoxyphenylthio group) which may have a substituent, an arylsulfinyl group (e.g., a benzenesulfinyl group and naphthalenesulfinyl group) which may have a substituent, an arylsulfonyl group (e.g., a benzenesulfonyl group, p-toluenesulfonyl group and p-methanesulfonylbenzenesulfonyl group) which may have a substituent, or a sulfamoyl group (e.g., N,N-disubstituted sulfamoyl group, for example, an N,N-diethylsulfamoyl group) which may have a substituent. The number of carbon atoms of each of these groups is preferably 1 to 50 and more preferably 1 to 20.
Among these groups, a halogen atom, an alkylthio group, an alkylsulfonyl group, an arylthio group and an arylsulfonyl group are preferable. These groups may have a substituent.
Z1 represents a carbamoyl group, an acyl group, an alkoxycarbonyl group or an aryloxycarbonyl group. Among these groups, a carbamoyl group is preferable, and a carbamoyl group having one or two and more preferably one hydrogen atom bonded on the nitrogen atom is particularly preferable.
As the carbamoyl group, those having 1-50 carbon atoms are preferable and those having 8-40 carbon atoms are more preferable. Specific examples of the carbamoyl group include a hexadecylcarbamoyl group, octadecylcarbamoyl group, 3- (2,4-di-tert-pentylphenoxy)propylcarbamoyl group, 4-dodecyloxyphenylcarbamoyl group, 2-chloro-5-dodecyloxycarbonylphenylcarbamoyl group and naphthylcarbamoyl group.
As-preferable examples of the aforementioned substituents, those mentioned as examples of the substituent that the group on the formula (1) may further have, can be mentioned. However, it is to be noted that a substituent that X1 may have as a further substituent thereon, does not include ahydroxy group, carboxyl group, mercapto group, aminosulfonyl group, carbonylaminosulfonyl group, sulfonylamino group, and sulfonylaminocarbonyl group.
Next, examples of the color-developing agent represented by the formula (2) will be explained. However, the scope of the present invention is not limited to these specific examples. 
Next, the compounds represented by the formula (3) or (4) for use in the third embodiment of the present invention will be explained in detail.
X2 in the formula (3) represents preferably an alkyl group having 1 to 8 carbon atoms which may have a substituent (e.g., a methyl group, ethyl group, trifluoromethyl group, trichloromethyl group or cyanomethyl group), or an aryl group having 6 to 15 carbon atoms which may have a substituent (e.g., a phenyl group, naphthyl group or m-nitrophenyl group).
Z2 represents a carbamoyl group, acyl group, alkoxycarbonyl group or aryloxycarbonyl group. Among these groups, a carbamoyl group is preferable and a carbamoyl group having one or two and preferably one hydrogen-atom bonded on the nitrogen atom is particularly preferable.
As the carbamoyl group, those having 1-50 carbon atoms are preferable and those having 8-40 carbon atoms are more preferable. Specific examples of the carbamoyl group include a hexadecylcarbamoyl group, octadecylcarbamoyl group, 3-(2,4-di-tert-pentylphenoxy)propylcarbamoyl group, 4-dodecyloxyphenylcarbamoyl group, 2-chloro-5-dodecyloxycarbonylphenylcarbamoyl group and naphthylcarbamoyl group.
In formula (4), R1 represents a substituent. Examples of the substituent include a straight-chain or branched, chain or cyclic alkyl group having 1 to 8 carbon atoms (e.g. trifluoromethyl, methyl, ethyl, propyl, heptafluoropropyl, isopropyl, butyl, t-butyl, t-pentyl, cyclopentyl, cyclohexyl, octyl, and 2-ethylhexyl); a straight-chain or branched, chain or cyclic alkenyl group having 2 to 8 carbon atoms (e.g. vinyl, 1-methylvinyl, and cyclohexen-1-yl); an alkynyl group having 2 to 8 carbon atoms in all (e.g. ethynyl and 1-propinyl), an aryl group having 6 to 15 carbon atoms (e.g. phenyl,. and naphthyl), an acyloxy group having 1 to 8 carbon atoms (e.g. acetoxy and benzoyloxy), a carbamoyloxy group having 1 to 8 carbon atoms (e.g. N,N-dimethylcarbamoyloxy), a carbonamido group having 1-to 8 carbon atoms (e.g. formamido, N-methylacetamido, acetamido, N-methylformamido, and benzamido), a sulfonamido group having 1 to 8 carbon atoms (e.g. methanesulfonamido, benzenesulfonamido, and p-toluenesulfonamido), a carbamoyl group having 1 to 8 carbon atoms (e.g. N-methylcarbamoyl, N,N-diethylcarbamoyl, and N-mesylcarbamoyl), a sulfamoyl group having 0 to 8 carbon atoms (e.g. N-butylsulfamoyl, N,N-diethylsulfamoyl, and N-methyl-N-(4-methoxyphenyl)sulfamoyl), an alkoxy group having 1 to 8 carbon atoms (e.g. methoxy, propoxy, isopropoxy, octyloxy, and t-octyloxy), an aryloxy group having 6 to 15 carbon atoms (e.g. phenoxy, 4-methoxyphenoxy, and naphthoxy), an aryloxycarbonyl group having 7 to 15 carbon atoms (e.g. phenoxycarbonyl and naphthoxycarbonyl), an alkoxycarbonyl group having 2 to 10 carbon atoms (e.g. methoxycarbonyl and t-butoxycarbonyl), an N-acylsulfamoyl group having 1 to 8 carbon atoms (e.g. N-propanoylsulfamoyl and N-benzoylsulfamoyl), an alkylsulfonyl group having 1 to 8 carbon atoms (e.g. methanesulfonyl, octylsulfonyl, and 2-methoxyethylsulfonyl), an arylsulfonyl group having 6 to 15 carbon atoms (e.g. benzenesulfonyl, and p-toluenesulfonyl), an alkoxycarbonylamino group having 2 to 8 carbon atoms (e.g. ethoxycarbonylamino), an aryloxycarbonylamino group having 7 to 15 carbon atoms (e.g. phenoxycarbonylamino and naphthoxycarbonylamino), an amino group having 0 to 8 carbon atoms (e.g. amino, methylamino, diethylamino, diisopropylamino, anilino, and morpholino), a cyano group, a nitro group, a carboxyl group, a hydroxyl group, a sulfo group, a mercapto group, an alkylsulfinyl group having 1 to 8 carbon atoms (e.g. methanesulfinyl and octanesulfinyl), an arylsulfinyl having 6 to 15 carbon atoms (e.g. benzenesulfinyl, 4-chlorophenylsulfinyl, and p-toluenesulfinyl), an alkylthio group having 1 to 8 carbon atoms (e.g. methylthio, octylthio, and cyclohexylthio), an arylthio group having 6 to 15 carbon atoms (e.g. phenylthio and naphthylthio), a ureido group having 1 to 15 carbon atoms (e.g. 3-methylureido, and 3,3-dimethylureido), a heterocyclic group having 2 to 10 carbon atoms (e.g. a 3-membered to 12-membered monocyclic ring or condensed ring having at least one hetero atom(s), such as nitrogen, oxygen, and sulfur, for example, 2-furyl, 2-pyranyl, 2-pyridyl, 2-thienyl, 2-imidazolyl, morpholino, 2-quinolyl, 2-benzimidazolyl, 2-benzothiazolyl, and 2-benzoxazolyl), an acyl group having 1 to 8 carbon atoms (e.g. acetyli benzoyl, and trifluoroacetyl), a sulfamoylamino group having 0 to 10 carbon atoms (e.g. N-butylsulfamoylamino and N-phenylsulfamoylamino), a silyl group having 3 to 10 carbon atoms (e.g. trimethylsilyl, and dimethyl-t-butylsilyl), and a halogen atom (e.g. a fluorine atom, a chlorine atom, and a bromine atom).
The above substituents may further have a substituent, and examples of such a substituent include those mentioned above as examples of R1. The total number of carbon atoms of the substituent is preferably 20 or less, more preferably 12. or less, and further preferably 8 or less.
m represents an inter of 0 to 4, and preferably 1 to 3.
When m is 2 or more, R1s can be the same or different, and may bond together to form a 5- to 7-membered ring.
Y1 represents an aryl group (e.g., a 4-hexadecyloxyphenyl group, 4-dodecanoylaminophenyl group or 2-chloro-4-hexadecyloxycarbonylaminophenyl group), an unsaturated heterocyclic group (e.g., a 2-(5-dodecanoylamino)pyridyl group, an acyl group (e.g., a dodecanoyl group or 4-decyloxybenzoyl group), an alkoxycarbonyl group (e.g., a tetradecylcarbonyl group or hexadecylcarbonyl group), an aryloxycarbonyl group (e.g., a 4-hexadecyloxyphenoxycarbonyl group or 4-dodecanoylaminophenoxycarbonyl group), a carbamoyl group (e.g., an N,N-dicyclohexylcarbamoyl group or N-dodecylcarbamoyl group) or a sulfonyl group (e.g., a dodecylsulfonyl group or hexadecylsulfonyl group), wherein these groups each have an alkyl group whose sum of carbon atoms is 6 or more, preferably 6 to 50, and more preferably 12 to 40, in total. Also, these groups may have a substituent. If the number of total carbon atoms of the alkyl group bonded to Y1 is 6 or more, this is effective to make the coupler of the formula (4) immobilized in a hydrophilic colloid layer and it makes easy to dissolve the coupler in a high-boiling point organic solvent, which is hence preferable.
Examples of the substituent of X2 in the formula (3) include the same substituents of R1 in the formula (4) except for a sulfamoyl group, sulfonamide group, carboxyl group, hydroxyl group, mercapto group and sulfamoylamino group. Given as examples of the substituent of Z2in the formula (3) and of Y1 in the formula (4) are the substituents having 1 to 50 carbon atoms explained for R1 in the formula (4).
Next, examples of the color-developing agent represented by the formula (3) will be explained. However, the scope of the present invention is not limited to these specific examples. 
Next, examples of the coupler represented by the formula (4) will be explained. However, the scope of the present invention is not limited to these specific examples. 
Next, a general method of synthesizing the compound of the present invention will be explained.